Conservatives believe they caught their Liberal rivals attempting to force Canadians to donate to the party before they can have their say on electoral reform.

It was an allegation that caught Democratic Institutions Minister Maryam Monsef by surprise in question period Monday.

Democratic Institutions Minister Maryam Monsef speaks in the House of Commons on Monday, June 13. (Photo: Adrian Wyld/CP)

Tory MPs rose to blast a panel discussion to be hosted this Sunday by the Dufferin-Caledon Federal Liberal Association. The group promoted the event online by noting how Monsef "challenged all 338 ridings in Canada to engage in active discussions" on Canada's electoral system this summer.

But the riding association initially charged tickets to the event, stating that since the meeting is "not sponsored by the Party or Government … there will be a cover charge of $10 to cover facility and other costs." The riding association made that fee "optional" shortly after question period.

Conservative House Leader Andrew Scheer told MPs that he now understands why Monsef has "been pushing town halls so hard," and dismissing the Tories' calls for a referendum. It's not because she wants input from Canadians, Scheer charged, but rather their donations.

"Is the reason the minister is so opposed to holding a referendum because her party cannot make money off one?" Scheer asked.

A screengrab of the Dufferin-Caledon Liberal website before it was changed.

Monsef said all MPs are tasked with ensuring that their constituents' voices are reflected in the report that will be put forward by the all-party committee studying changes to the electoral system.

"I want to ensure that all members are following all of the rules and regulations put forward by this House to make sure that we carry ourselves with integrity," Monsef said.

'What a sham'

Tory MP Blake Richards also hammered the government over the event.

"It turns out Liberals are even charging Canadians to attend their town halls," he said. "What a sham."

Monsef told the House she was "surprised to be made aware" of the development.

"We will be looking into this matter," she said.

"If the minister wants to get to the bottom of it, she does not have to look very far," Richards said. "It is right there on the Liberal website."

Scott Reid, the Tory critic for democratic institutions, later said Liberals were giving a new meaning to the phrase: "penny for your thoughts."

Tory MP was invited

But a member of the riding association says the event was put together by local members solely to foster discussion on electoral reform.

George denHaan, vice-president of the Dufferin-Caledon Federal Liberal Association, told The Huffington Post Canada via email that the riding's MP — Conservative David Tilson — declined an invitation to participate in the panel. Two political science professors and a local business leader are poised to discuss the merits of the ranked ballot system, proportional representation, and the status quo of first-past-the-post.

"While we initially opted to charge a very modest fee of $10 to help cover the costs, we have decided to make this optional to ensure that everyone can come and participate," denHaan said in the email.

"We are looking forward to the forum and invite all local residents to come and engage in the discussion."

Democratic Institutions Minister Maryam Monsef rises during question period in the House of Commons.

Monsef answers another question in the House of Commons.

Minister of Democratic Institutions Maryam Monsef answers a question during question period in the House of Commons.

UP NEXT: Rookie MPs to Watch

A community organizer, Monsef was born in Afghanistan. She fled the Taliban and came to Canada as a refugee with her widowed mother and sisters in 1996.
Monsef, 30, will serve as minister for democratic institutions.

Joly, 36, made a name for herself by finishing second to ex-Liberal cabinet minister Denis Coderre in the Montreal mayoral race in 2013. A lawyer and communications expert who was heavily involved in her community, she ran for the Liberals and beat ex-Bloc MP-turned-New Democrat Maria Mourani.
Joly was named minister of Canadian heritage.

Caesar-Chavannes has been named parliamentary secretary to the prime minister.
She first gave the Tories a fright in a 2014 byelection to fill the seat left behind by the late Jim Flaherty. Though she lost to Whitby's then-mayor Pat Perkins, the race ended up being a lot closer than many expected.
In a rematch, Caesar-Chavannes, an entrepreneur and research consultant, won by almost 2,000 votes.

Deltell, a longtime member of Quebec's National Assembly, served as leader of the right-wing Action Démocratique du Québec until that party merged with Coalition Avenir Quebec a few years ago.
He was considered a star recruit for the Conservatives, who have struggled in the province. Deltell easily defeated his Liberal challenger by nearly 20,000 votes. The NDP incumbent finished third.

Despite not having a seat, Beaulieu was elected leader of the Bloc Quebecois in June 2014. He gave up the role just before the start of the election to make room for former leader Gilles Duceppe.
Though Duceppe lost his bid for a seat, Beaulieu was victorious and will soon have a chance to make his mark in Parliament.

Blair was chief of the Toronto Police Service from 2005 to 2015. He sparked controversy with his handling of the 2010 G20 protests in the city and publicly clashed with controversial ex-mayor Rob Ford.
A police officer for 40 years, Blair says he was approached by the Tories and New Democrats before he decided to run for the Trudeau Liberals.
He has been named parliamentary secretary to the minister of justice and Attorney General.

Rayes, the popular mayor of Victoriaville since 2009, was courted for months to run federally. His pursuit of a nomination was interpreted as a sign of Conservative momentum in the province.
Rayes rolled to victory, besting his nearest competitor (a Liberal) by more than 4,000 votes.

Though New Democrats lost more than half their seats and saw many high-profile MPs defeated, Blaikie's razor-thin victory over a Tory incumbent was a bright spot.
Blaikie, 31, is the son of NDP stalwart Bill Blaikie, who served as an MP from 1979 to 2008. His sister, Rebecca, is president of the NDP.

Leslie, a retired general who led Canadian troops in Afghanistan, was one of the Liberals' star recruits. He served as Trudeau's foreign policy and defence adviser and unseated a Conservative incumbent in the Ottawa riding.
He has been named chief government whip.

Morneau, the former executive chair of Morneau Shepell, one of Canada's largest human resources firms, has landed the coveted finance portfolio.

Wilson-Raybould, a former Crown prosecutor and regional chief of the B.C. Assembly of First Nations will serve as justice minister and attorney general.

Watts, the very popular former mayor of Surrey, likely would have landed in cabinet if Harper's Conservatives won again. Instead, she will be a fresh face in the opposition benches.
Mayor of B.C.'s second-largest city from 2005 to 2014, she was one of just two Conservatives endorsed by GreenPAC, a group dedicated to environmental causes.

Sajjan, a retired lieutenant colonel who also served in Afghanistan, was the first Sikh to command a Canadian Army regiment. He also served as a Vancouver police officer for 11 years.
He has been named defence minister.

Liepert was an MLA in Alberta for 12 years and served as both minister of health and energy. He challenged controversial, longtime MP Rob Anders for the Tory nomination and even told Jason Kenney to "mind his own business" after the cabinet minister endorsed his rival.
Liepert easily won his seat and, days later, bashed the way the Conservative Party ran the national campaign. Liepert, it seems, is no shrinking violet.

Mihychuk was an NDP MLA in Manitoba from 1995 to 2004, serving as minister of industry, trade, and mines, and later minister of intergovernmental affairs.
She has been named minister of employment.

McKenna, a social justice lawyer, was a former legal advisor for the United Nations peacekeeping mission in East Timor and founded Canadian Lawyers Abroad (now known as Level), a charity focused on global justice issues.
She will serve as minister of the environment and climate change.

Malcolmson captured the Vancouver Island riding for the NDP, winning by more than 6,000 votes.
She is a former chairwoman of the Islands Trust Council, and was elected to that body four times. Her experience in local government could mean a key role in an NDP caucus now depleted of many veterans MPs.

McCrimmon ran for the leadership of the Liberal Party in 2013 despite never holding elected office. A former lieutenant colonel in the Royal Canadian Air Force, McCrimmon was the first female air navigator and first woman to command a Canadian Forces flying squadron.
She has been named parliamentary secretary to the minister of veterans affairs and associate minister of national defence.

Hehr, an Alberta MLA from 2008 to 2015, was one of just two Liberals elected in Calgary. Grits were shut out of that city for almost 50 years.
The 45-year-old will serve as minister of veterans affairs and associate minister of national defence.

Philpott is a family physician, associate professor at the University of Toronto, and former chief of the department of family medicine at Markham Stouffville Hospital. She unseated controversial parliamentary secretary Paul Calandra by nearly 4,000 votes.
She will serve as minister of health.

A respected Edmonton city councillor since 2007, Sohi immigrated to Canada from India 35 years ago and served time behind bars as a political prisoner in India.
He has been named minister of infrastructure.

Qualtrough, a lawyer and former Paralympian, will serve as minister of sport.
Legally blind, Qualtrough won three Paralympic and four World Championship medals for Canada in swimming and was president of the Canadian Paralympic Committee.

Hajdu, executive director of Thunder Bay's largest homeless shelter, will serve as status of women minister.

O'Regan, a former host of "Canada AM" and CTV journalist, unseated an NDP incumbent in the Newfoundland riding.
While well-known for his broadcasting career, O'Regan also worked as an assistant to Jean Charest, back when he was a Progressive Conservative environment minister. He also worked as a speechwriter for former Liberal Newfoundland and Labrador premier Brian Tobin.

The 35-year-old, who worked for the Kitchener-Waterloo Multicultural Centre, will serve as minister of small business and tourism.

Duclos, a renowned economics professor at Laval University, will serve as minister of families, children and social development.

Carr, a former Manitoba MLA and deputy leader of the Manitoba Liberal Party, unseated a Tory incumbent by an astounding 17,000 votes.
He will serve as minister of natural resources.

Mendicino, a former federal prosecutor, knows how to go up against big names and win. First, he beat Tory-turned-Liberal Eve Adams in a nomination battle and won the Toronto seat held by finance minister Joe Oliver by nearly 6,000 votes.
He could be headed for big things in a Trudeau government.

Fuhr is a former CF-18 fighter pilot who served with the Canadian Air Force for 20 years. Though his riding had been reliably Conservative, he unseated the Tory incumbent by more than 4,000 votes.
Fuhr wrote a blog for HuffPost last year detailing how he went from being a lifelong Conservative to a Liberal candidate. He could be considered for a cabinet or parliamentary secretary role.

Ouellette, a Cree academic who served almost 20 years in the Canadian Armed Forces, surprised many with a strong campaign for mayor of Winnipeg in 2014.
He unseated colourful NDP incumbent Pat Martin in a race that turned personal at times. Ouellette is one of a record 10 indigenous MPs elected to the House of Commons.